Derivatives (Derivatives Not Designated as Hedging Instruments - Foreign Exchange Contracts) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Derivative assets - Fair value	$ 708,610	$ 330,316
Derivative liabilities - Fair value	506,019	256,528
Derivatives not designated as hedging instruments
Derivative [Line Items]
Notional amount	19,523,762	20,540,031
Derivative assets - Fair value	708,546	330,316
Derivative liabilities - Fair value	503,906	251,744
Derivatives not designated as hedging instruments \| Foreign exchange contracts
Derivative [Line Items]
Notional amount	1,832,383	4,839,661
Derivative assets - Fair value	19,134	54,637
Derivative liabilities - Fair value	14,530	47,024
Foreign exchange contracts \| Customer Counterparty \| Derivatives not designated as hedging instruments \| Forwards and spot
Derivative [Line Items]
Notional amount	959,820	3,581,036
Derivative assets - Fair value	8,480	45,911
Derivative liabilities - Fair value	11,884	40,591
Foreign exchange contracts \| Customer Counterparty \| Derivatives not designated as hedging instruments \| Swaps
Derivative [Line Items]
Notional amount	11,373	6,889
Derivative assets - Fair value	358	16
Derivative liabilities - Fair value	45	84
Foreign exchange contracts \| Customer Counterparty \| Derivatives not designated as hedging instruments \| Written options
Derivative [Line Items]
Notional amount		87,036
Derivative assets - Fair value		127
Derivative liabilities - Fair value		0
Foreign exchange contracts \| Customer Counterparty \| Derivatives not designated as hedging instruments \| Collars
Derivative [Line Items]
Notional amount	1,172	2,244
Derivative assets - Fair value	0	0
Derivative liabilities - Fair value	26	14
Foreign exchange contracts \| Customer Counterparty \| Derivatives not designated as hedging instruments \| Foreign exchange contracts
Derivative [Line Items]
Notional amount	972,365	3,677,205
Derivative assets - Fair value	8,838	46,054
Derivative liabilities - Fair value	11,955	40,689
Foreign exchange contracts \| Financial Counterparty \| Derivatives not designated as hedging instruments \| Forwards and spot
Derivative [Line Items]
Notional amount	205,113	207,492
Derivative assets - Fair value	1,367	1,400
Derivative liabilities - Fair value	124	507
Foreign exchange contracts \| Financial Counterparty \| Derivatives not designated as hedging instruments \| Swaps
Derivative [Line Items]
Notional amount	486,211	702,391
Derivative assets - Fair value	8,383	6,156
Derivative liabilities - Fair value	1,951	4,712
Foreign exchange contracts \| Financial Counterparty \| Derivatives not designated as hedging instruments \| Purchased options
Derivative [Line Items]
Notional amount		87,036
Derivative assets - Fair value		0
Derivative liabilities - Fair value		127
Foreign exchange contracts \| Financial Counterparty \| Derivatives not designated as hedging instruments \| Collars
Derivative [Line Items]
Notional amount	168,694	165,537
Derivative assets - Fair value	546	1,027
Derivative liabilities - Fair value	500	989
Foreign exchange contracts \| Financial Counterparty \| Derivatives not designated as hedging instruments \| Foreign exchange contracts
Derivative [Line Items]
Notional amount	860,018	1,162,456
Derivative assets - Fair value	10,296	8,583
Derivative liabilities - Fair value	$ 2,575	$ 6,335

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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